Download IPP Protection Requirements for IPP Interconnection

DG Protection Requirements for DG Interconnection
Protection Requirements for DG Interconnection
Basic functional requirements for all cases:

The Typical Protection Requirements apply mainly to the FIRST distributed
generator to be connected onto a particular distribution feeder. If there are
more than ONE distributed generators connected onto the same distribution
feeder, the interactions between distributed generators must be studied to
determine the impacts, especially islanding issues.

Increase in distribution fault levels due to DG fault contribution must be
reviewed in order to ensure correct interrupting rating of distribution
equipment and proper protection setting coordination.

DG must meet FortisAlberta’s Voltage-Flicker and Power Quality
requirements.
Typical Protection Requirements for DG Interconnection: Case 1
Generator Type:
Interconnection Type:
Synchronous Generator
Export to Utility
PROTECTION REQUIREMENT
Transfer tripping the DG
interconnecting breaker from
substation feeder breaker
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
(Note: If DG islanding with utilities’
distribution load is possible for any
single contingency condition, additional
transfer tripping logic/scheme will be
required)
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Transfer tripping the DG
interconnecting breaker from any
feeder OCR (Oil Circuit Recloser)
which, if opened, could create an
islanding situation of the DG with
utilities’ distribution feeder load
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
DG must have protective device(s) to
detect and clear any distribution fault
FUNCTIONAL PURPOSE
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder breaker is opened for
any reason
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder OCR is opened for any
reason
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared (If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
must be effectively grounded.
To prevent and/or minimize the
injury/damage of personnel (including
on the interconnected feeder
DG must have over/under voltage
protection
DG must have over/under frequency
protection
the public) and equipment caused by
any distribution feeder fault
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage
Typical Protection Requirements for DG Interconnection: Case 2
Generator Type:
Interconnection Type:
Synchronous Generator
NO Export to Utility
PROTECTION REQUIREMENT
Directional over-current protection
(looking into the utility system at the
interconnection point) to trip the
interconnecting breaker at the DG site
(i.e. Trip on any current flow into the
utility system from the DG)
FUNCTIONAL PURPOSE
To prevent any possibility of export
from the DG to the utility system
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
DG must have over/under voltage
protection
DG must have over/under frequency
protection
To provide fault detection and fault
clearing for any distribution fault on the
interconnected feeder
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared. If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
must be effectively grounded.
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage
Typical Protection Requirements for DG Interconnection: Case 3
Generator Type:
Interconnection Type:
Induction Generator
Export to Utility
PROTECTION REQUIREMENT
Transfer tripping the DG
interconnecting breaker from
substation feeder breaker, unless the
DG can NOT self excite
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
(Note: If DG islanding with utilities’
distribution load is possible for any
single contingency condition, additional
transfer tripping logic/scheme will be
required)
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Transfer tripping the DG
interconnecting breaker from any
feeder OCR (Oil Circuit Recloser)
which, if opened, could create an
islanding situation of the DG with
utilities’ distribution feeder load, unless
the DG can NOT self excite
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
FUNCTIONAL PURPOSE
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder breaker is opened for
any reason
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder OCR is opened for any
reason
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared. If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
DG must have protective device(s) to
detect and clear any distribution fault
on the interconnected feeder, unless
the DG can NOT self excite
DG must have over/under voltage
protection
DG must have over/under frequency
protection
must be effectively grounded.
To prevent and/or minimize the
injury/damage of personnel (including
the public) and equipment caused by
any distribution feeder fault
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage
Typical Protection Requirements for DG Interconnection: Case 4
Generator Type:
Interconnection Type:
Induction Generator
NO Export to Utility
PROTECTION REQUIREMENT
Directional over-current protection
(looking into the utility system at the
interconnection point) to trip the
interconnecting breaker at the DG site
(i.e. Trip on any current flow into the
utility system from the DG)
FUNCTIONAL PURPOSE
To prevent any possibility of export
from the DG to the utility system
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
DG must have over/under voltage
protection
DG must have over/under frequency
protection
To provide fault detection and fault
clearing for any distribution fault on the
interconnected feeder
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared (If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
must be effectively grounded.
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage
Typical Protection Requirements for DG Interconnection: Case 5
Generator Type:
Interconnection Type:
Inverter Generator
Export to Utility
PROTECTION REQUIREMENT
Transfer tripping the DG
interconnecting breaker from
substation feeder breaker, unless the
DG can NOT self excite
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
(Note: If DG islanding with utilities’
distribution load is possible for any
single contingency condition, additional
transfer tripping logic/scheme will be
required)
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Transfer tripping the DG
interconnecting breaker from any
feeder OCR (Oil Circuit Recloser)
which, if opened, could create an
islanding situation of the DG with
utilities’ distribution feeder load, unless
the DG can NOT self excite
Transfer tripping to have Fail Safe
feature (i.e. the DG interconnecting
breaker will be tripped if
telecommunication is not available for
any reason)
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
FUNCTIONAL PURPOSE
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder breaker is opened for
any reason
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
To prevent islanding of DG with utilities’
distribution feeder load, in the event
that, the feeder OCR is opened for any
reason
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared. If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
must be effectively grounded.
DG must have protective device(s) to
detect and clear any distribution fault
on the interconnected feeder, unless
the DG can NOT self excite
DG must have over/under voltage
protection
DG must have over/under frequency
protection
To prevent and/or minimize the
injury/damage of personnel (including
the public) and equipment caused by
any distribution feeder fault
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage
Typical Protection Requirements for DG Interconnection: Case 6
Generator Type:
Interconnection Type:
Inverter Generator
NO Export to Utility
PROTECTION REQUIREMENT
Directional over-current protection
(looking into the utility system at the
interconnection point) to trip the
interconnecting breaker at the DG site
(i.e. Trip on any current flow into the
utility system from the DG)
FUNCTIONAL PURPOSE
To prevent any possibility of export
from the DG to the utility system
Directional over-current protection on
the interconnected feeder breaker,
unless the maximum fault contribution
from the DG is less than the
instantaneous setting of the nondirectional protection of the
interconnected feeder breaker
Configuration of the utility side (i.e. 25
kV side) of the interconnecting
transformer must be grounded Y
To prevent the unnecessary tripping of
the interconnected feeder for any
distribution fault occurred on the
adjacent distribution feeder
DG must have over/under voltage
protection
DG must have over/under frequency
protection
To provide fault detection and fault
clearing for any distribution fault on the
interconnected feeder
To prevent any over-voltage condition
imposed on distribution equipment
caused by line-to-ground fault after the
utility source is cleared (If generator
side (i.e. low voltage) configuration is
grounded wye, the generator windings
must be effectively grounded.
To protect the connected distribution
equipment and load from over/under
voltage damage
To protect the connected distribution
equipment and load from over/under
frequency damage